The rise of synthetic opioids known as nitazenes has created a growing public health concern in Ireland, particularly for individuals living with both severe mental illness and opioid use disorder. A recent article published in the Irish Journal of Psychological Medicine highlights the urgent need to expand access to naloxone, a life-saving medication that can reverse opioid overdoses, in response to this emerging threat.1 The authors argue that patients with a ‘dual diagnosis’ of mental illness and substance use disorder are among the most vulnerable groups in society and require targeted interventions to reduce overdose deaths.

Research has shown that around one-half of people with severe mental illness also experience a substance use disorder.2 Patients with opioid dependence face especially high risks because of the increasing presence of potent synthetic opioids in the Irish drug market. Nitazenes, which were first developed in the 1950s but never approved for medical use due to their extreme potency, are estimated to be between 50 and 500 times stronger than heroin. Their strength significantly increases the likelihood of fatal overdose, particularly when users are unaware that substances have been contaminated with nitazenes.

Ireland has already begun to experience the consequences of this trend. Drug-related deaths increased steadily between 2016 and 2020,3 and in 2021 opioids were involved in the majority of overdose deaths. Since late 2023, several clusters of overdoses linked to nitazenes have occurred in Dublin and Cork, affecting dozens of individuals.4 These synthetic opioids have been found mixed into heroin, cocaine, counterfeit tablets, benzodiazepines, and even cannabis products, making them difficult to detect and increasing the danger for users.

Naloxone has emerged as one of the most effective tools for preventing overdose deaths. The medication rapidly reverses opioid-related respiratory depression and has already saved lives during recent overdose incidents in Ireland. However, access to naloxone remains inconsistent, and uptake among patients is often low. The article describes an intervention carried out at the HSE National Drug Treatment Centre in Dublin, where patients received one-to-one overdose prevention training from doctors and pharmacists. Following this initiative, the percentage of patients receiving take-home naloxone kits increased dramatically from 12% to 61%.

The authors stress that naloxone provision should become a routine part of opioid agonist treatment services across Ireland. They also recommend broader public health measures, including peer-to-peer education, reducing stigma surrounding naloxone use, and improving collaboration between mental health, addiction, and community harm reduction services. Patients experiencing active symptoms of mental illness may struggle to engage with traditional healthcare services due to paranoia, disorganised thinking, or social isolation, making assertive outreach especially important.

On a national level, the article suggests that Ireland should consider allowing naloxone to be available over the counter in pharmacies, as has been done successfully in several European countries. The recent introduction of take-home naloxone kits for prisoners being released from custody is highlighted as another positive development.

Ultimately, the article warns that Ireland must prepare for the growing threat posed by synthetic opioids. Expanding access to naloxone and strengthening integrated mental health and addiction services could play a critical role in preventing overdose deaths and protecting some of the country’s most vulnerable individuals.

1    McNicholas R, Sweeney N, Fenton F and Keenan E (2025) Enhancing naloxone provision in patients with comorbid mental illness and opioid use disorder amidst the rise of nitazenes in Ireland. Ir. J. Psychol. Med, Early online, pp. 1-2. Available from: https://www.drugsandalcohol.ie/44146/

2    Drake RE, Mueser KT and Brunette MF (2007) Management of persons with co-occurring severe mental illness and substance use disorder: program implications. World Psychiatry 6, 131–136.

3    Hanrahan MT, Millar SR, Phillips KP, Reed TE, Mongan D and Perry IJ (2022) Problematic opioid use in Ireland, 2015–2019. Dublin: Health Research Board. Available from: https://www.drugsandalcohol.ie/35856

4    Killeen N, Lakes R, Webster M, et al. (2024) The emergence of nitazenes on the Irish heroin market and national preparation for possible future outbreaks. Addict. 119(9), 1657–1658.